Electric and acoustic bass instruments including the bass guitar, the upright double bass and cello provide the rhythmic foundation to musical compositions. Typical of the many types of popular musical genres that can be played on string instruments are rock, funk, soul, salsa, hip-hop, Cajun zydeco, classical and country.
Musicians performing musical compositions on acoustic or amplified bass instruments employ multiple methods of string activation. The traditional methods for activation of single or multiple bass strings to produce musical notes include: the combined use of fingers and thumb; use of a single finger-gripped plectrum commonly referred to as a pick; use of finger or thumb mounted picks; and use of a strung bow. More recent variations to traditional bass string activation methods include quickly plucking or snapping a string above the fretboard to produce notes with a popping undertone, and the use of a glancing thumb strike on a string to produce notes with a slapping undertone.
In a single performance a musician may employ any or all of the traditional and non-traditional methods of string activation. Common to all of the methods is constant, repetitive movement of the muscles, ligaments and joints comprising the human hand including the fingers, palm, wrist, forearm and elbow. A rehearsal session or live performance lasting several hours or more can lead to fatigue with loss of mobility in the fingers, palm and wrist of the string activating hand. Excessive overuse can eventually cause injury to the ligaments, joints and nerves of the hand, fingers, forearm and elbow.